The present invention concerns the provision of novel cationic collectors for the concentration of ores by flotation and a method for making the same. More specifically, the invention relates inexpensive, highly soluble materials intended for replacement of the tall oil-amine derivatives in the second stage of the two stage flotation process for the benefication of phosphate ores for fertilizer manufacture.
Conventionally, in the two stage flotation process, the finely ground phosphate rock is mixed with water and small amounts of fatty acid, sodium hydroxide and kerosine (or fuel oil) and charged to a flotation cell where air is bubbled through the suspension. The oil coats the phosphate particles which attach themselves to air bubbles and rise to the surface were they are skimmed off. Sand particles are not wetted by the oil and sink to the bottom where they are drawn off continuously. Perfect separation is not obtained, however. To obtain further concentration, the product from the first flotation (rougher) step is washed with dilute sulfuric acid which removes most of the chemicals with which the phosphate particles are coated and, with water, which removes the oil as a slime. The deslimed material is then subjected to a second flotation step in which the reagents are an amine or amine derivative, sodium hydroxide, and a frothing agent such as a five or six carbon alcohol. These reagents coat the sand which floats to the surface leaving the phosphate concentrate which is removed from the bottom of the second cell as the underflow or unfloated portion of the ore.